1. Field of the Invention
The present invention relates generally to handwriting data entry, and more particularly to methods and systems for facilitating data entry using a pen input device.
2. Description of the Related Art
Digital writing instruments, interchangeably referred to herein as xe2x80x9cdigital pensxe2x80x9d regardless of whether they write in ink, can be used to capture pen strokes on paper and digitize them, so that the pen strokes can be converted by handwriting recognition software to a digitally-stored record of the writing. In this way, a laborious, tedious step in modern written communication, namely, the manual transcribing of handwriting into a computerized word processor, is eliminated, greatly increasing productivity.
Accordingly, digital pen systems can digitize pen strokes across a substrate, by sensing, in some fashion, the time-dependent position of the pen and converting the positions to pen strokes, for input of digital representations of the pen strokes to a handwriting recognition device. As recognized herein, magnetic-type systems can be used in which a special pen generates or alters a magnetic field as it is moved across a piece of paper, with the field being sensed by a special pad over which the paper is placed. Similarly, ultrasonic systems can be used in which a special pen generates or alters an ultrasonic signal as the pen is moved across a piece of paper, with the signal being sensed by a special pad over which the paper is placed.
As another alternative, as disclosed in co-pending U.S. patent application Ser. No. 09/226,778, filed Jan. 7, 1999 and assigned to the same assignee as is the present application, a conventional pen can be moved across a special substrate to alter an electric field, with the field anomalies caused by the pen movement being sensed and correlated to pen positions.
As recognized by the present invention, all of the above-mentioned systems require special pads to sense pen or stylus motion. As further recognized herein, it is desirable to enable a writer to write characters on a conventional paper substrate while recording pen motion without requiring the use of a special underlying pad and without requiring the use of special paper, so that the user can write on any convenient substrate without having to transport and use a relatively bulky pad. The present invention moreover recognizes that it is desirable to provide a system that can, but not must, use special paper for particular applications.
A digital pen includes an elongated body defining a writing tip, and a laser is oriented on the body to direct light onto a substrate against which the writing tip is positioned. The pen also includes a detector that receives interference patterns of light (xe2x80x9cspecklesxe2x80x9d) generated by the laser and reflected by the substrate. A contact sensor is supported by the pen body, and the contact sensor outputs a contact signal that represents whether the writing tip is positioned against the substrate. Also, a processor receives signals from the detector and in response thereto outputs position signals representative of positions of the pen.
In a preferred embodiment, the detector, processor, and a memory are all supported by the pen body. The memory stores position signals from the processor, such that the position signals later can be retrieved from the memory and processed by a handwriting recognition module to render signals representing alpha-numeric characters. Preferably, the processor sends position signals to the memory only when the contact signal indicates that the writing tip is positioned against the substrate, so that when a writer lifts the pen from the substrate, the pen position can be tracked but position signals are not recorded.
If desired, the substrate can include optical codes that are detectable by the detector. The codes represent at least positions, and the detector outputs at least one code signal in response to detecting an optical code. Furthermore, the detector outputs at least one speckle signal and the processor uses code signals and speckle signals to generate absolute position signals. The absolute position signals represent a pen position relative to at least one dimension defined by the substrate. Additionally, the optical codes can represent data including form entry fields.
In another aspect, a digital input device includes an elongated body defining a distal tip, and at least one laser is oriented on the body to direct light toward the vicinity of the distal tip. At least one detector is oriented on the body to receive reflections of laser light from a substrate against which the distal is from time to time positioned. Moreover, at least one contact sensor is provided on the body, and at least one processor is also on the body. As set forth further below, the processor communicates with the detector and the contact sensor.
In still another aspect, a processor is supported by an elongated writing implement, and the processor receives digitized representations of speckle frames that are generated by a detector on the body as the writing implement is moved against a substrate. The processor includes logic to convert the speckle frames to position signals representing positions of a distal tip of the writing implement. In accordance with the present invention, the logic includes comparing at least one current speckle frame to at least one previous speckle frame to render a pen position.
Thus, the invention can include a general purpose computer programmed according to the inventive steps herein. The invention can also be embodied as an article of manufacturexe2x80x94a machine componentxe2x80x94that is used by a digital processing apparatus and which tangibly embodies a program of instructions that are executable by the digital processing apparatus to undertake the present invention. This invention is realized in a critical machine component that causes a digital processing apparatus to perform the inventive method steps herein.
In yet another aspect, a processor that is supported by an elongated writing implement receives a digitized representation of optical reflectivity of a substrate generated by a light detector on the body as the writing implement is stroked across a substrate. The substrate includes preprinted optical codes to provide position information and visible tags viewable to the writer. In a preferred embodiment, tag processing means categorizes writing during or after handwriting capture. The tags can include at least one tag function or category chosen from the group including new, undo, done, email, fax, name, address, company, phone number, fax number, day, time, subject, drawing, call, expense, notes, project, order, personal, to do, and urgent. With this in mind, the tag processing means includes logical means to cause fax or email transmissions of categorized handwriting.
The details of the present invention, both as to its structure and operation, can best be understood in reference to the accompanying drawings, in which like reference numerals refer to like parts, and in which: